RxJava：在不同线程上合并可观察对象

Question

我需要合并在不同线程上运行的两个可观察对象。示例代码为

val obs1 = Observable
    .create<Int> { emitter ->
        emitter.onNext(1)
        emitter.onComplete()
    }
    .subscribeOn(Schedulers.newThread())

val obs2 = Observable.just(2)

val obs = Observable
    .just(1, 2)
    .flatMap {
        Observable.merge(
            Observable.just(it).filter { it == 1 }.flatMap { obs1 },
            Observable.just(it).filter { it == 2 }.flatMap { obs2 }
        )
    }
    .serialize()

obs.blockingSubscribe(::println)

期望输出为1, 2，有时会得到2, 1。似乎serialize()没有帮助。如何获得正确的排放指令-1, 2？

Answer 1